In-soil Biodegradation Behavior of Chitosan-Coated Phosphorylated Starch Films

Grupo de Materiales Compuestos Termoplásticos (CoMP), Instituto de Investigaciones en Ciencia y Tecnología de Materiales (INTEMA), Facultad de Ingeniería, Universidad Nacional de Mar del Plata (UNMdP) y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Colón 10850, (7600) Mar del Plata, Argentina.

Adv. Mater. Lett., 2019, 10 (12), pp 907-912

DOI: 10.5185/amlett.2019.0017

Publication Date (Web): Nov 01, 2019

Copyright © IAAM-VBRI Press

E-mail: danila.merino@fi.mdp.edu.ar

Abstract

Novel starch-based films were previously proposed as agricultural mulches and their main properties were critically addressed. In this report, the effects of chemical modification by crosslinking (phosphorylation) and surface functionalization with chitosan on corn starch-films biodegradability were studied. The biodegradability assay was performed in soil using a professional substrate. The biodegradation and disintegration of samples were followed by measuring their weight loss (WL), water sorption (WS) and changes in appearance (by photographs). Additionally, changes in surface morphology at microscopic level were investigated by scanning electron microscopy (SEM), while structural and chemical changes were evaluated by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Results indicate that neither the chemical modification by phosphorylation, nor the chitosan-functionalization of the surface produced changes in films biodegradation time, which is a positive result. All materials degrade almost completely in three months following a three-step mechanism that involves plasticizer leaching, microbial development, bio-erosion of the surface and the starch molecular weight diminution. © VBRI Press.

Keywords

biodegradable, environmentally friendly, fungal attack, sustainable agriculture.